PENGANTAR OBAT OTONOM DAN GANGLION

Dimas P.NugrahaDepartemen Farmakologi dan Terapi FK UR

The efferent nerves of the autonomic nervous system

The autonomic nerves innervate smooth muscles, cardiac tissue and glands.

Both parasympathetic and sympathetic systems have ganglia where ACh is the transmitter of the preganglionic fibers; ACh acts on nicotinic receptors on the postganglionic nerves.

ACh is also the neurotransmitter at cells of the adrenal medulla, where it acts on nicotinic ACh receptors to cause release of the catecholamines epinephrine (Epi) and NE into the circulation

The somatic nerves innervate skeletal muscle directly without a ganglionic relay

Response to symphatetic activation

Sympathetic Fight or Flight Response

Response to parasymphatetic Activation

Action of sympathetic and parasympathetic nervous systems on effector organs

Efek utama yang dimediasi oleh Alpha and Beta adrenoceptors

Site at Which Drugs Act To Modify Cell Functions

Example of Cholonergic and adrenergic Drug Treatment : Glaucoma

Penyakit glaucoma tipe tertentu dapat diobati dengan memodifikasi aktivitas simpatik dan parasimpatik di bola mata.

Cholinergic agonist seperti pilocarpin dapat meningkatkan pengeluaran aqueos humor melalui canalis schlemm

Adrenergic antagonis seperti Timolol menurunkan aliran masuk aqueos humor sehingga dapat mengurangi gejala glaucoma

Drugs That act On The Autonomic nervous System

Process Affected

Drug Example Site Action

Action potential propagation

Local anesthetics, tetrodotoxin,1 saxitoxin2

Nerve axons Block sodium channels; block conduction

Transmitter synthesis

Hemicholinium Cholinergic nerve terminals: membrane

Blocks uptake of choline and slows synthesis

Transmitter storage

Reserpine Adrenergic terminals: vesicles

Prevents storage, depletes

Transmitter release

Botulinum toxin Cholinergic vesicles

Prevents release

Tyramine, amphetamine

Adrenergic nerve terminals

Promote transmitter release

Process Affected

Drug Example Site Action

Transmitter reuptake after release

Cocaine, tricyclic antidepressants

Adrenergic nerve terminals

Inhibit uptake; increase transmitter effect on postsynaptic receptors

Receptor activation or blockade

Norepinephrine Receptors at adrenergic junctions

Binds receptors; causes contraction

Nicotine Receptors at nicotinic cholinergic junctions (autonomic ganglia, neuromuscular end plates)

Binds nicotinic receptors; opens ion channel in postsynaptic membrane

Tubocurarine Neuromuscular end plates

Prevents activation

Atropine Receptors, parasympathetic effector cells

Binds muscarinic receptors; prevents activation

Enzymatic inactivation of transmitter

Neostigmine Cholinergic synapses (acetylcholinesterase)

Inhibits enzyme; prolongs and intensifies transmitter action

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